If I numbered
bus svcs
Yishun: 80x, 81x (Feeders); 85x, 86x
Sembawang: 82x (Feeders); 88x
Woodlands: 90x, 91x (Feeders); 95x, 96x
Bukit Panjang: 92x (Feeders); 89x, 97x
CCK: 93x (Feeders); 87x, 98x
Bukit Batok: 94x (Feeders); 99x
Yishun Svcs:
Feeders 800, 803, 804, 805, 806, 811, 812
Trunks 851, 852, 853, 854, 855, 857, 860, 861 (171)
Sembawang Svcs:
Feeder 822 (882), 829A/B (859A/B)
Trunks 880 (980), 881 (981), 883, 887 (167)
Woodlands Svcs:
Feeders 900, 901, 902, 903, 904, 911, 912, 913
Trunks 950, 951 (178), 952 (926), 955 (925), 956 (856), 957
(187), 958 (858), 959 (169), 960, 961, 962, 963, 964, 965, 966,
969
Bukit Panjang Svcs:
Feeders 920, 922
Trunks 890 (180), 895 (75), 896 (176), 897 (177), 899 (700),
970, 972, 974 (184), 975, 979
CCK Svcs:
Feeders 930 (300), 931 (301), 932 (302), 937 (307), 938
(308)
Trunks 871 (BPS1), 872 (172), 877 (67), 980 (190), 983, 985, 987
(927), 988 (188)
Bukit Batok Svcs:
Feeders 941, 945, 947
Trunks 990, 993 (173), 996 (106), 997 (77), 999 (189)
*() = denotes current numbers