grid deduction - Double feature: Bibliophile edition

_{This puzzle is part 12 of the Double feature series (first part here). The series will conclude in "Double features: The wrap-up".}

---

Rules of Tents and Trees¹

• Place a number of tents into the grid.


• There are exactly as many tents as there are trees.


• Each tent is attached to one tree, which is adjacent to it horizontally or vertically. No tree has more than one tent attached to it, but there may be multiple tents around the same tree as long as each of them is attached to their own unique tree.


• Two tents cannot be adjacent to one another horizontally, vertically or even diagonally.



• The numbers above each column and to the left of each row give the number of tents on that row or column.

Across
3. Arab Republic of Syria is in utterly secret revolution (7)
6. A small one was a giant leap for hamsters? Perhaps the other way around (4)
8. Worried, Simon had to present a warning (8)
9. The one preceding the first of her kind (3)
11. Japanese artist's monologue part (3)
12. Verbally chase away a moccasin, maybe (4)
15. Mother of partially historical leader buried in mausoleum (3)

16. Making a turntable finally play back high-pitched noise (4)
18. Moderator loses right to proceed becoming dictator (4)
19. Man and father destroyed in rampage, leading to violent outburst (4)
20. Energy field's centre protects a small relief (4)

Down
1. Native Americans incorporated a shaved head (5)
2. Between friends, Russell and Ivan regularly ejected from Medvedev's home (4)
4. Influential 1001 Nights originally collected by by American soldier (7)
5. Being upset can elicit initial skin reaction (4)
7. The original, original Van Gogh (4)

10. Science fiction writer's name is never spelled incorrectly (5)
12. Bratwurst – maybe mostly ignored American food (4)
13. Beer and doughnut enthusiast is a writer of some repute (5)
14. Literary Jane's legal successor reported (4)
17. Quiet about the male chromosome's victims (4)

_{¹ Paraphrased from the rules on Cross+A.}

Solve both puzzles to answer the question: What does the bookkeeper have many of?

Answer

What does the bookkeeper have many of?

Successive Pairs

The clues:

Across
 3. Arab Republic of Syria is in utterly secret
    revolution (7)                                     TUNISIA = Syri_A IS IN UT\<_terly
 6. A small one was a giant leap for hamsters?

    Perhaps the other way around (4)                   STEP = PETS\<
 8. Worried, Simon had to present a warning (8)        ADMONISH = (SIMON HAD)*
 9. The one preceding the first of her kind (3)        EVE = cryptic def.?
11. Japanese artist's monologue part (3)               Yoko ONO = m_ONO_logue
12. Verbally chase away a moccasin, maybe (4)          SHOE = homophone of SHOO
15. Mother of partially historical leader buried
    in mausoleum (3)                                   MAO = MA + O(f)
16. Making a turntable finally play back high-pitched
    noise (4)                                          YELP = PL(a>E)Y\<
18. Moderator loses right to proceed becoming (Idi)    AMIN = A(d)MIN - (procee)D

     dictator (4)                                          (Thanks, Braegh!)
19. Man and father destroyed in rampage, leading to    RAGE = RA(m + pa)GE
    violent outburst (4)
20. Energy field's centre protects a small relief (4)  EASE = (A + S) in (E + (fi)E(ld))

Down
 1. Native Americans incorporated a shaved head (5)    INCAS = INC + A + S(haved)
 2. Between friends, Russell and Ivan regularly
    ejected from Medvedev's home (4)                   RUSS = RUSS(ia) - I(v)A(n)
 4. Influential 1001 Nights originally collected by

    American soldier (7)                               SEMINAL = (MI + N(ights)) in SEAL
 5. Being upset can elicit initial skin reaction (4)   ACNE = CAN* + E(licit)
 7. The original, original Van Gogh (4)                THEO = THE + O(riginal)
10. Science fiction writer's name is never spelled     VERNE = NEVER*
    incorrectly (5)
12. Bratwurst - maybe mostly ignored American food (4) SAAG = SA(us)AG(e)
13. Beer and doughnut enthusiast is a writer of
    some repute (5)                                    HOMER = ddef. 
14. Literary Jane's legal successor reported (4)       EYRE = homophone of HEIR
17. Quiet about the male chromosome's victims (4)      PREY = P + RE + Y

The grid with the cells from Glorfindel's answer highlighted:

]1